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3. SOWING SEED

Tree seed can be sown directly into polypots, or can be sown into seedbeds or seedtrays and can be pricked out into poly pots later.
Large seed that can easily be handled one at a time or seed that germinates well can be sown directly into polypots. Direct sowing into polypots avoids the damage to roots or the chance of seedlings dying if they are pricked-out badly. However, if the seed germinates poorly space is wasted with empty polypots in the nursery beds:


Space can be saved in the nursery by sowing seed in trays or beds. This also allows different seed to be treated in different ways more easily. For instance, it is easier to shade seedtrays by moving them under cover or to protect a seedbed from rodents by putting up a wire mesh, than it is to do these things to a whole standbed of polypots.
Seed beds or seed trays should be used when seed viability is low or when seed is small or it takes a long time to germinate.


3.1 POLYPOTS

Large, easily handled seed or seed you know has a high viability can be sown directly into polypots.
Species that are usually sown into polypots include acacias, badahar chiuri, chuletro, koiralo, phaledo, pines, siris and tanki.



Polypots should be filled to within 1 cm of the top at least a week before they are to be sown and the soil in them kept moist.
The polypots should be well watered the evening before the seed is to be sown
............. and lightly watered again just before the seed is sown.



Push the seed into the soil to no more than half a centimetre deep.
Alternatively, first make a hole with a small stick and drop the seed into it.

High germination seed.

Low germination seed.

Normal sowing

To make sure that at least one seedling grows in each polypot, two or more seeds are usually sown in each pot. If you know germination is very good (more than 8 out of 10 seeds germinate) then in half of the polypots sow 1 seed and in the other half sow 2.
If germination is very low (less than 6 out of every 10 seeds germinate) then sow 3 seeds in every polypot.
Otherwise sow 2 seeds in each polypot.



After sowing, the polypots should be filled to the top with washed, seived sand.
After filling the polypots a mulch of straw should be placed over them or shades put up over them to protect against heavy rain and hot sun. They should also be watered again.
Check regularly to see if the seed is germinating. Once germination starts remove the mulch, if it was used.




After germinating some polypots may have 2 or more seedlings whilst others may be empty:
‘Extra’ seedlings will have to be pricked-out into the empty polypots. If there are more than enough seedlings to fill all the empty polypots do not leave more than 1 in any of the polypots.
If 2 or more seedlings are left to grow in a single polypot they will both become weak and small and neither of them will be any good for planting.
Pull up, cut or break off the extra seedlings as soon as possible to allow the one that is left to grow on more healthily.


When the seedlings are about 2 cm tall the shade over them should be gradually removed. Firstly for 1 hour in the morning and 1 hour in the late afternoon when the sun is not very strong. Over about a week the time without shade should be gradually increased in the morning and afternoon until, on the last day, they are left unshaded all day.



3.2 SEEDTRAYS

The main advantage of seedtrays is that they can be carried. This means that they can be put under shelter from heavy rain or hot sun easily and they can be carried to the standout beds where the pricking-out of the seedlings is done. They are especially good for germinating very small seed.
Seedtrays can be made from wood. They should be about 40 cm long, 30 cm wide and 10 cm deep.
Drainage should be provided by 7 mm holes drilled in the bottom, or by making the base from wooden slatts.
Or seedtrays can be made by cutting old oil tins in half lengthways, bending back the sharp, cut edges and punching drainage holes in the bottom.




For pines, fir and eucalypts, and other species which are all pricked out soon after germinating, washed seived sand is good in the seedtrays.
Some species, such as utis, figs and gogan, are kept longer in the seedtrays and so need extra nutrients. They need a mix of half washed seived sand and half seived forest top soil.
Compost should never be used in seedtrays because it can cause damping-off by fungi and death of the small seedlings.



Fill the seedtray to within 1 cm of the top with the soil mix that you are using.
 Water the seed tray......



Level and firm the surface of the soil with a block of wood. This is very important to get the best germination of small seed.
Broadcast the seed evenly over the surface. If the seed is very small mix it with some clean, dry sand before you broadcast it .....



Cover the seed thinly with some more seived, washed sand....
Level and firm the sand again .....



Cover the seed tray with a mulch of rice husks or straw or pine needles .......
 Water the seedtray again ....


The seedtrays should be kept under cover and looked at several times a day to make sure that they are not drying out or becoming too wet.
When germination has nearly finished remove the mulch.



Seedtrays can be watered by standing them in 2 to 5 cm of water in a flat bottomed basin for 10–20 minutes twice a day.
This prevents the small seed and seedlings from being damaged by water sprinkling from a watering can.
When the seedlings are almost big enough to be pricked out they should be hardened off by putting them out in the sun for a few hours each day.



3.3 PREPARATION OF SEED BEDS

Seed beds can be used to germinate larger seeds such as bakaino, bhimal, champ, lapsi, lankuri, paingyu and siltimur.
The beds should be built in a part of the nursery that is well drained and which is not shaded.
They should be no wider than 1m so that the naike can work in them easily.
Mark the edge of the seed-bed out with string and sticks …
Dig a trench around the outside of the string markers about 5–10cm deep.




Set large flat stones into the trench so that they stand at least 15cm above ground level......
Put a 5cm layer of coarse gravel or stones in the bottom of the bed for drainage, and compact it. Then 2–3cm of seived forest top soil on top of the gravel, and compact again.
Finally fill the bed to within 2cm of the top with a mix of half seived sand and half seived forest top soil, and compact this layer as well.



3.4 SOWING IN SEED BEDS

Before sowing the seed make sure the surface of the bed is perfectly level.




If it is not flat water may form puddles on the bed and seed would be washed away or covered too deeply by soil.
Water the bed lightly ......




Large seed such as bakaino, katus, lapsi, paingyo, oak and okhar can be sown in drills running across the beds 5–10cm apart.
Smaller seeds should be broadcast onto the bed and pressed into the bed with a flat board.
Cover the seed with a thin layer of sand, 5 mm.




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